1. Related Applications
This application is related to the commonly assigned applications of:
a. Satellite Dish Antenna Support Split Rim--U.S. Pat. No. Des. 285,685 is issued to John R. Winegard and Keith B. Cowan, PA1 b. Satellite Dish Antenna Support Rim--U.S. Pat. No. Des. 285,792 John R. Winegard and Keith B. Cowan, PA1 c. Satellite Dish Antenna Outer Rim--U.S. Pat. No. Des. 285,074 issued to John R. Winegard and Keith B. Cowan, and PA1 d. Satellite Dish Antenna Apparatus, U.S. Pat. No. 4,568,945 issued to John R. Winegard and Keith B. Cowan.
2. Field of the Invention
This invention relates to the design and construction of a satellite dish antenna having modular parabolic reflector segments. More particularly, it relates to the design of the support rib between the modular segments of a satellite dish antenna.
3. Discussion of the Prior Art
Over the past decade, the use of satellite dish antennas by the consuming public has increased substantially. Two general categories of dish antennas have been involved. The first category contains those dish antennas made of solid material, such as fiberglass, which are molded into a parabolic shape. These antennas generally have high gain and signal reception, but are expensive to ship and have a high wind load when installed. The second category of dish antennas relates to those antennas having a screen-mesh material for the reflective surface. Such antennas are generally assembled in sections and, therefore, are less expensive to ship. They also exhibit low wind load characteristics but have overall lower gain and signal reception. The reason for the lower gain in such screen-mesh antennas is, in primary part, due to their approximation of the true parabolic shape such as through use of a number of linearly shaped segments.
Prior to making an application for the above-identified U.S. Pat. No. 4,568,945 a patentability search was performed. The results of this search are repeated here as follows:
______________________________________ Inventor U.S. Pat No. Issue Date ______________________________________ E. Gerhard 2,181,181 Nov. 28, 1939 S.E. Mautner 2,471,828 May 31, 1949 L. Lewin et al. 2,985,851 May 23, 1961 D.S. Kennedy 2,997,712 Aug. 22, 1961 R.E. Thomas 3,234,550 Feb. 8, 1966 E. Kelly 3,286,270 Nov. 15, 1966 A.C. Maier 3,406,404 Oct. 15, 1968 H.A. Payne 3,543,278 Nov. 24, 1970 Rushing et al. 3,635,547 Jan. 18, 1972 Quequen 3,725,945 Apr. 3, 1973 Taggart, Jr. 3,832,717 Aug. 27, 1974 Taggart 3,971,023 July 20, 1976 Toshio 4,169,688 Oct. 2, 1979 Vines 4,201,991 May 6, 1980 Vines 4,249,184 Feb. 3, 1981 Davis 4,257,207 Mar. 24, 1981 Taggart 4,268,835 May 19, 1981 Bannister 1,604,899 Dec., 1981 Sayovitz 4,314,253 Feb. 2, 1982 Palmer et al. 4,315,265 Feb. 9, 1982 Hibbard et al. 4,378,561 Mar. 29, 1983 ______________________________________
The 1983 patent to Hibbard (U.S. Pat. No. 4,278,561) relates to a parabolic reflector antenna formed by assembling identical pie-shaped sections of parabolically curved plastic. The sections are preferably glued together along the joints provided along the radial edges.
The patents issued to Taggart (U.S. Pat. Nos. 3,832,717; 3,971,023; and 4,268,835) all relate to parabolic reflectors comprised of generally triangular shaped petals joined together in an edgewise overlapping relationship. In the '023 and '717 patents, an outer rim is provided around the dish antenna to provide outer support. In the '835 patent, a tubular outer segmented rigid rim is provided wherein the opposing ends slidably engage with the next segment. The edgewise overlapping petals are bolted together by means of a plurality of holes.
The 1970 patent issued to Payne (U.S. Pat. No. 3,543,278) also relates to a sectional parabolic reflector wherein individual petal sections are held together by a support molding 17 as shown in FIG. 3 which in turn is bolted to the edges of each section.
The two patents issued to Vines (U.S. Pat. Nos. 4,201,991 and 4,249,184) relate to a parabolic antenna kit comprised of a number of pre-stressed support arms (made from wood) which supports a plurality of screen reflector segments. A tensioning cable engages the outer ends of each support arm an provides sufficient tension, upon assembly, to stress the support arms into a parabolic shape. The parabolic screen is connected to the wood support arms by means of staples or twisted wires.
The patents issued to Sayovitz (U.S. Pat. No. 4,314,253), to Kelly (U.S. Pat. No. 3,286,270), to Maier (U.S. Pat. No. 3,406,404), and to Palmer (U.S. Pat. No. 4,315,265) all relate to collapsible dish antennas of various shapes and configurations. The antennas are assembled as a whole and can be shipped in a collapsed position and at the site can be selectively moved into the operative position.
These patents and other publications are presented and discussed in the aforesaid application. The present invention relates to an improvement in the manner of affixing the pre-formed screen-mesh segments to the support ribs of a satellite dish antenna. The prior art approach is shown in FIG. 1 which corresponds to FIG. 2 of U.S. Pat. No. 4,568,945 identified above. In FIG. 1, the pre-formed screen-mesh 10 of a satellite dish antenna, not shown, engages a support rib 20 comprising an upper rib locking member 30 and a lower locking rib member 40. Both locking members 30 and 40 are made from elongated extruded aluminum pieces and are stretch-formed to follow parabolic curves 50 and 60. The length of each member 30 and 40 is dependent upon the size of the dish antenna, in question.
The upper member 30 is inserted into the lower member 40 by pushing it in the direction of arrow 70. The upper rib member 30 includes a flat upper surface having two downwardly extending prongs 32. Each prong 32 terminates in a hook 34. As shown in FIG. 1, the hooks 34 on each prong points away from the other outwardly directed hook.
The lower rib member 40 has a downwardly extending vertical plate 42 extending the full longitudinal length of the lower support rib 40. This vertical plate 42 provides structural strength for rib 40. At the upper end of the vertical plate 42 are formed two circular cavities 44 also extending the longitudinal length of the lower support rib 40. The circular cavities 44 have an opening directly facing each other. Extending upwardly from each channel 44 are a pair of vertical parallel plates 46 which terminate at their upper ends into outwardly extending horizontal formed channels 48. The ends 12 of the screen-mesh 10 are inserted between the ridges 36 and the channels 48. The upper support member 30 is then forced to engage the lower support member 40 so that the hooks 34 engage the circular cavities 44 the entire longitudinal length of the rib member 20. In this fashion, the rib member 20 provides a continual force along the entire longitudinal length of the support rib 20 to firmly hold the screen-mesh 10.
In FIG. 2, a split rib configuration 100 corresponding to FIG. 7 of U.S. Pat. No. 4,568,945 is set forth having an upper member 110 and a lower split rib member 120. The upper split rib 110 engages the end 12 of the screen-mesh 10 in a fashion similar to that priorly discussed in FIG. 1 for rib member 20. The upper member 110 contains an upper surface having a triangular-shaped elongated ridge 112 extending downwardly at one end. The upper surface is cantilevered from a vertical plate 114 which has an outwardly extending locking lip 116 formed thereon slightly above the mid section of plate 114. The lower split rib member 120 also has a vertical plate 122 which terminates in a substantially circular channel 124 which opens towards the locking lip 116. The upper end of circular channel 124 is connected through a second vertical plate which terminates in a rearwardly extending horizontal channel 126. In operation, the locking ridge 112 firmly engages the end 12 of the screen-mesh 10 and firmly holds it in the horizontal channel 126. As discussed in the afore-referenced patent application, the split rib member 120 shown in FIG. 2 comprises one-half of a symmetrical split rib configuration which is bolted together and which forms the sides of a screen-mesh petal.
As can be observed in FIG. 2, four separate extruded pieces are required to interconnect adjacent petal segments of a satellite dish antenna together. The present invention sets forth a structure which performs the same function as set forth in FIG. 2 with only two extruded pieces thereby substantially reducing manufacturing and inventory costs.